rs190192954

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_001267550.2(TTN):c.24622G>A(p.Glu8208Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000316 in 1,613,682 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. E8208E) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 3.81

Variant links:

Genes affected

TTN (HGNC:12403): (titin) This gene encodes a large abundant protein of striated muscle. The product of this gene is divided into two regions, a N-terminal I-band and a C-terminal A-band. The I-band, which is the elastic part of the molecule, contains two regions of tandem immunoglobulin domains on either side of a PEVK region that is rich in proline, glutamate, valine and lysine. The A-band, which is thought to act as a protein-ruler, contains a mixture of immunoglobulin and fibronectin repeats, and possesses kinase activity. An N-terminal Z-disc region and a C-terminal M-line region bind to the Z-line and M-line of the sarcomere, respectively, so that a single titin molecule spans half the length of a sarcomere. Titin also contains binding sites for muscle associated proteins so it serves as an adhesion template for the assembly of contractile machinery in muscle cells. It has also been identified as a structural protein for chromosomes. Alternative splicing of this gene results in multiple transcript variants. Considerable variability exists in the I-band, the M-line and the Z-disc regions of titin. Variability in the I-band region contributes to the differences in elasticity of different titin isoforms and, therefore, to the differences in elasticity of different muscle types. Mutations in this gene are associated with familial hypertrophic cardiomyopathy 9, and autoantibodies to titin are produced in patients with the autoimmune disease scleroderma. [provided by RefSeq, Feb 2012]

TTN links:

TTN-AS1 (HGNC:44124): (TTN antisense RNA 1) This gene encodes a non-coding RNA transcribed from the opposite strand to the titin gene. [provided by RefSeq, Aug 2016]

TTN-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PP2

Missense variant where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.1101456).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.24622G>A	p.Glu8208Lys	missense_variant	85/363	ENST00000589042.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.24622G>A	p.Glu8208Lys	missense_variant	85/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-16020C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000145

AC:

AN:

152096

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000435

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000197

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000443

AC:

AN:

248320

Hom.:

AF XY:

0.0000371

AC XY:

AN XY:

134684

show subpopulations

Gnomad AFR exome

AF:

0.000517

Gnomad AMR exome

AF:

0.0000580

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000891

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000198

AC:

AN:

1461468

Hom.:

Cov.:

AF XY:

0.0000248

AC XY:

AN XY:

727004

show subpopulations

Gnomad4 AFR exome

AF:

0.000628

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.000145

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.000175

AC XY:

AN XY:

74412

show subpopulations

Gnomad4 AFR

AF:

0.000433

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000135

Hom.:

Bravo

AF:

0.000257

ESP6500AA

AF:

0.000517

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000745

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Nov 10, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Oct 24, 2020	- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

May 01, 2014

Variant classified as Uncertain Significance - Favor Benign. The Glu6964Lys vari ant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 2/3868 African American chromosomes by the NHLBI Exom e Sequencing Project (http://evs.gs.washington.edu/EVS/; dbSNP rs190192954). Com putational prediction tools and conservation analysis do not provide strong supp ort for or against an impact to the protein, though 1 mammal (bush-tailed rat) c arries a lysine (Lys) at this position raising the possibility that this change may be tolerated. In summary, the clinical significance of the Glu6964Lys varian t is uncertain. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 31, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.077

BayesDel_addAF

Benign

-0.37

BayesDel_noAF

Benign

-0.40

Cadd

Benign

Dann

Benign

0.84

Eigen

Benign

0.13

Eigen_PC

Benign

0.21

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.65

T;T;.;T

M_CAP

Benign

0.022

MetaRNN

Benign

0.11

T;T;T;T

MetaSVM

Benign

-0.95

MutationTaster

Benign

0.98

D;D;D;D;D;D

PrimateAI

Benign

0.42

PROVEAN

Benign

-1.8

N;.;.;.

REVEL

Benign

0.26

Sift

Benign

0.28

T;.;.;.

Polyphen

0.33

.;.;B;B

Vest4

0.43

MVP

0.17

MPC

0.12

ClinPred

0.033

GERP RS

6.2

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over